According to the four Sunni schools, there are three types of (asaba) residuaries: a residuary by himself ('asabah binafsiha), a residuary through another ('asabah bi ghayriha), and a residuary along with another (asabah ma'a ghayriha)
A residuary by himself' includes all males between whom and the decedent there is no intervening woman, and the meaning of being such a residuary is that he is independent of others (in his right to inherit as a residuary), and that he is a residuary in all cases and situations. A 'residuary through another' and 'residuary along with another,' are residuaries in certain cases without being so in others, as will become clear later.
The residuaries by themselves' are the closest of residuaries and inherit in the following order:
Then the son's son, how low-so-ever; he takes the place of his father,
Then the father, then
The paternal grandfather, how high-so-ever;
then the full brother;
then the half brother by father;
then the son of the full brother;
then the son of the half brother by father;
then the full paternal uncle,
then the consanguine paternal uncle (who is father's half brother
then the son of the full paternal uncle,
then the son of the consanguine paternal uncle.
If some of them exist along with others, the son will supersede the father, in the sense that the father will take his fard (share)—whichis one-sixth -- and the son will take the remainder as a residuary.
According to the four Sunni schools, the son's son will similarly supersede the father, and the father will supersede the paternal grand father. They differ regarding the paternal grandfather as to whether he will supersede the brothers in inheritance or if they inherit jointly with him, so that all of them are considered as belonging to the same class. Abu Hanifah observes: The grandfather will supersede the brothers and they will not inherit anything along with him. The Imámi, the Shafi`i and the Maliki schools state:
They will inherit with him because they belong to his class.
Among the residuaries, those related from both sides will supersede those related from only one side. Hence a full brother will supersede a consanguine brother and the full brother's son will supersede a consanguine brother's son. Similarly, in the case of paternal uncles the degree of their nearness (to the decedent) is taken into consideration, and the nearest is preferred. Therefore, the decedent's paternal uncle supersedes his father's paternal uncle, and he in turn will supersede the grand father's paternal uncle.
The following four female relatives are considered residuaries through another:
1. daughter or daughters,
2. son's daughter or daughters,
3. full sister or sisters,
4. consanguine sister or sisters
It is known that all the above-mentioned inherit as sharers in the absence of a brother.l3 one of them is entitled to a half, and if more, to two-thirds, and if they have a brother they inherit as residuaries— according to the four Sunni schools -- but not if they are alone, and will share the heritage with him, the male receiving twice the share of females.
As regards 'residuaries along with another,' they are full or consanguine sister or sisters that inherit along with a daughter or son's daughter. Therefore, a sister or sisters inherit as 'sharers' if there i8 no daughter or son's daughter inheriting along with them, and inherit as residuaries with a daughter or son's daughter. Hence the daughter or the son's daughter will take her share and the full or consanguine sister or sisters will take the remainder, thereby becoming residuaries along with the daughter.
From this explanation it becomes clear that a full or consanguine sister inherits in three different ways. She is a sharer if she has no brother and the decedent no daughter, a 'residuary through another' if she has a brother, and a 'residuary along with another' if the decedent has a daughter. The same applies in the case of two or more sisters. It also becomes clear that full and consanguine paternal uncles will not share in the heritage along with the daughter except in the absence of full or consanguine brothers and sisters.
The four Sunni schools concur that if there is a single residuary without any sharers, he will inherit the whole heritage, and in the presence of a sharer he will take the remainder after the sharer has taken his share. If there is no residuary, according to the Maaliki and the Shaafi'ee schools, the excess will escheat to the bayt al-mal, and according to the Hanafi and the \anbalí schools it goes to the sharers by way of 'return' (radd), and the estate will not escheat to the bayt al-mal in the absence of sharers, residuaries and distant kindred.
The Residuaries From the Imámi's Viewpoint
The Imámís do not recognize these three different kinds of residuaries and limit the heirs to 'sharers' and 'residuaries' without differentiating between male and female residuaries. Hence, a single son is entitled to the whole estate; a single daughter and a single sister too are similarly entitled. They classify the heirs, both males and females, into three categories:
1. Parents and children, how lowsoever.
2. Brothers and sisters (and their children), how lowsoever, and grandparents, both paternal and maternal, how highsoever.
3. Paternal and maternal uncles and aunts and their children.
Whenever there exists a male or a female heir in the higher category, it will prevent all others belonging to the lower category from inheriting, whereas in the opinion of all the other schools these different categories may combine and inherit together, and at times all the three categories may inherit together, such as a mother along with a uterine sister and a full paternal uncle, in which case the mother receives one third, the sister one-sixth, and the uncle the remainder.